Thulium-178

Properties and data of the isotope ¹⁷⁸Tm.

Contents

General data

Name of the isotope:Thulium-178; Tm-178Symbol:¹⁷⁸Tm or 17869TmMass number A:178 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:109Isotopic mass:177.95264(43) u (atomic weight of Thulium-178)Nuclide mass:177.9147914 u (calculated nuclear mass without electrons)Mass excess:-44.11556 MeVMass defect:1.531763052 u (per nucleus)Nuclear binding energy:1426.82809236 MeV (per nucleus)
8.01588816 MeV (average binding energy per nucleon)Separation energy:S_N = 4.72(50) MeV (first neutron)
S_P = 8.55(64) MeV (first proton)Half-life:300 nsDecay constant λ:2310490.6018665 s^-1Specific activity α:7.861073367231 × 10⁺²⁷ Bq g^-1
2.124614423576 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2008

Radioactive Decay

Half-life T_½ = 300 ns respectively 3 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁷⁸Yb	?	5.58(40) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 109) and isobaric (same nucleon number A = 178) with Thulium-178. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 109	Isobar A = 178
68	¹⁷⁷Er
69	¹⁷⁸Tm	¹⁷⁸Tm
70	¹⁷⁹Yb	¹⁷⁸Yb
71	¹⁸⁰Lu	¹⁷⁸Lu
72	¹⁸¹Hf	¹⁷⁸Hf
73	¹⁸²Ta	¹⁷⁸Ta
74	¹⁸³W	¹⁷⁸W
75	¹⁸⁴Re	¹⁷⁸Re
76	¹⁸⁵Os	¹⁷⁸Os
77	¹⁸⁶Ir	¹⁷⁸Ir
78	¹⁸⁷Pt	¹⁷⁸Pt
79	¹⁸⁸Au	¹⁷⁸Au
80	¹⁸⁹Hg	¹⁷⁸Hg
81	¹⁹⁰Tl	¹⁷⁸Tl
82	¹⁹¹Pb	¹⁷⁸Pb
83	¹⁹²Bi
84	¹⁹³Po
85	¹⁹⁴At
86	¹⁹⁵Rn